Estimated Date: 1860
Name: Stethoscope ,Modified Cammanns with pleximeter
Manufacturer: Sharp and Smith, 100 Randolph Street, Chicago Ill.
Description: Banjo shaped cardboard box 9” x 5” widest. Lid has label Sharp and Smith, Chicago. Contains a modified Cammann’s. Bell is ebony, 3.5” long in total, 1 3/8” dia. Total length with woven cloth, rubberized tubing 15.5”. The head piece has a circular hinge with a spring and patent date April 1882 and Ford NY and Caswell Hazard on the other side. There is also a 2.5” hard rubber pleximeter. This version is unique because of the internally sprung hinge to apply tension to the ear.
Reference 1: 57